A display panel using an Organic Electro-Luminescence (OEL) device has been known.
A system for an OEL device that emits light is classified into two types: passive matrix method and active matrix method. The active matrix method is a drive system using a thin film transistor (TFT).
FIG. 1 is a diagram illustrating array of light-emitting element (passive type) of a conventional full-color organic display panel. As shown in this figure, the organic display panel has an image display arrangement including a plurality of light-emitting elements 41 arranged in a matrix state, and each light-emitting element 41 has light emitting parts of red R, green G, and blue B.
FIG. 2 is a diagram illustrating an outline structure of substrate section 51a of light-emitting element 41 of the full-color organic display panel (passive type). As shown in this figure, substrate section 51a has first electrodes 53 made of indium/tin oxide (ITO) and the like provided on substrate 52 made of transparent glass and the like. Plural first electrodes 53 are arranged in a stripe state in parallel with each other. In addition, electrical insulating films 54 and banks 55 are set on substrate 52 including first electrodes 53. Insulating films 54 and banks 55 are formed so as to cross first electrodes 53 at a right angle and with a predetermined interval. Further, banks 55 are provided so as to project from substrate 52. Furthermore, banks 55 are formed at positions so as to expose part of first electrodes 53.
In addition, on a part of electrode 53 on which the banks are not formed, at least one layer of OEL layer 56 is formed. Further, on OEL layer 56, second electrode 57 extending substantially perpendicular to an extending direction of first electrode 53.
Banks 55 prevents adjacent second electrodes 57 from shorting out by separating adjacent second electrodes 57 from each other. Therefore, a sectional shape of bank 55 is preferably in an overhang shape such as an inverted trapezoid and the like as shown in FIG. 2.
Moreover, an organic material constituting OEL layer 56 is susceptible to moisture in general, and a material susceptible to moisture is used also in a material constituting banks 55. Thus, in light-emitting element 41, a surface on which banks 55 and OEL layer 56 are formed is sealed by a sealing section (such as a glass tube, a protective film and the like, for example) as shown in FIG. 3. FIG. 3 is a sectional view illustrating a structure of light-emitting element in a conventional full-color organic display panel, in which FIG. 3A shows light-emitting element 41 sealed by glass tube 68, FIG. 3B shows light-emitting element 41 sealed by protective film 69 with a low moisture permeability. Both FIGS. 3A and 3B are sectional views along a longitudinal direction of first electrode 53.
In light-emitting element 41 configured as above, OEL layer 56 at a part where first electrode 53 and second electrode 57 cross each other at a right angle while being driven emits light. The emitted light transmits substrate 52 and proceeds toward a display surface direction (See Patent Documents 1 and 2, for example).    Patent Document 1: Japanese Patent Application Laid-Open No. H11-040370    Patent Document 2: Japanese Patent Application Laid-Open No. 2000-089690